Oyekan Anthony, Dalton Jonathan, Fourman Mitchell S, Ridolfi Dominic, Cluts Landon, Couch Brandon, Shaw Jeremy D, Donaldson William, Lee Joon Y
1Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh.
2Pittsburgh Orthopaedic Spine Research Group, Pittsburgh.
Neurosurg Focus. 2023 Jan;54(1):E5. doi: 10.3171/2022.10.FOCUS22605.
The aim of this study was to investigate the effect of degenerative spondylolisthesis (DS) on psoas anatomy and the L4-5 safe zone during lateral lumbar interbody fusion (LLIF).
In this retrospective, single-institution analysis, patients managed for low-back pain between 2016 and 2021 were identified. Inclusion criteria were adequate lumbar MR images and radiographs. Exclusion criteria were spine trauma, infection, metastases, transitional anatomy, or prior surgery. There were three age and sex propensity-matched cohorts: 1) controls without DS; 2) patients with single-level DS (SLDS); and 3) patients with multilevel, tandem DS (TDS). Axial T2-weighted MRI was used to measure the apical (ventral) and central positions of the psoas relative to the posterior tangent line at the L4-5 disc. Lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and PI-LL mismatch were measured on lumbar radiographs. The primary outcomes were apical and central psoas positions at L4-5, which were calculated using stepwise multivariate linear regression including demographics, spinopelvic parameters, and degree of DS. Secondary outcomes were associations between single- and multilevel DS and spinopelvic parameters, which were calculated using one-way ANOVA with Bonferroni correction for between-group comparisons.
A total of 230 patients (92 without DS, 92 with SLDS, and 46 with TDS) were included. The mean age was 68.0 ± 8.9 years, and 185 patients (80.4%) were female. The mean BMI was 31.0 ± 7.1, and the mean age-adjusted Charlson Comorbidity Index (aCCI) was 4.2 ± 1.8. Age, BMI, sex, and aCCI were similar between the groups. Each increased grade of DS (no DS to SLDS to TDS) was associated with significantly increased PI (p < 0.05 for all relationships). PT, PI-LL mismatch, center psoas, and apical position were all significantly greater in the TDS group than in the no-DS and SLDS groups (p < 0.05). DS severity was independently associated with 2.4-mm (95% CI 1.1-3.8 mm) center and 2.6-mm (95% CI 1.2-3.9 mm) apical psoas anterior displacement per increased grade (increasing from no DS to SLDS to TDS).
TDS represents more severe sagittal malalignment (PI-LL mismatch), pelvic compensation (PT), and changes in the psoas major muscle compared with no DS, and SLDS and is a risk factor for lumbar plexus injury during L4-5 LLIF due to a smaller safe zone.
本研究旨在探讨退变性腰椎滑脱（DS）对腰椎侧方椎间融合术（LLIF）期间腰大肌解剖结构及L4-5安全区的影响。
在这项单机构回顾性分析中，确定了2016年至2021年间因腰痛接受治疗的患者。纳入标准为腰椎磁共振成像（MR）和X线片资料完整。排除标准为脊柱创伤、感染、转移瘤、过渡性解剖结构或既往手术史。共有三个年龄和性别倾向匹配的队列：1）无DS的对照组；2）单节段DS（SLDS）患者；3）多节段串联DS（TDS）患者。采用轴向T2加权MRI测量腰大肌相对于L4-5椎间盘后切线的顶点（腹侧）和中心位置。在腰椎X线片上测量腰椎前凸（LL）、骨盆入射角（PI）、骨盆倾斜角（PT）、骶骨倾斜角（SS）以及PI-LL失配情况。主要结局指标为L4-5水平腰大肌的顶点和中心位置，通过逐步多元线性回归计算得出，回归模型纳入人口统计学数据、脊柱骨盆参数及DS程度。次要结局指标为单节段和多节段DS与脊柱骨盆参数之间的相关性，采用单因素方差分析及Bonferroni校正进行组间比较。
共纳入230例患者（92例无DS，92例SLDS，46例TDS）。平均年龄为68.0±8.9岁，185例患者（80.4%）为女性。平均体重指数（BMI）为31.0±7.1，平均年龄校正Charlson合并症指数（aCCI）为4.2±1.8。各组间年龄、BMI、性别及aCCI相似。DS分级每增加一级（从无DS到SLDS再到TDS）均与PI显著增加相关（所有关系p<0.05）。TDS组的PT、PI-LL失配、腰大肌中心位置及顶点位置均显著高于无DS组和SLDS组（p<0.05）。DS严重程度每增加一级（从无DS到SLDS再到TDS），腰大肌中心位置独立向前移位2.4 mm（95%可信区间1.1-3.8 mm），顶点位置独立向前移位2.6 mm（95%可信区间1.2-3.9 mm）。
与无DS及SLDS相比，TDS表现出更严重的矢状面排列不齐（PI-LL失配）、骨盆代偿（PT）以及腰大肌变化，并且由于安全区较小，是L4-5 LLIF期间腰丛神经损伤的危险因素。
